Cache.Insert Method
Definition
Important
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Inserts an item into the Cache object. Use one of the versions of this method to overwrite an existing Cache item with the same key parameter.
Overloads
| Insert(String, Object, CacheDependency, DateTime, TimeSpan, CacheItemPriority, CacheItemRemovedCallback) |
Inserts an object into the Cache object with dependencies, expiration and priority policies, and a delegate you can use to notify your application when the inserted item is removed from the |
| Insert(String, Object, CacheDependency, DateTime, TimeSpan, CacheItemUpdateCallback) |
Inserts an object into the Cache object together with dependencies, expiration policies, and a delegate that you can use to notify the application before the item is removed from the cache. |
| Insert(String, Object, CacheDependency) |
Inserts an object into the Cache that has file or key dependencies. |
| Insert(String, Object) |
Inserts an item into the Cache object with a cache key to reference its location, using default values provided by the CacheItemPriority enumeration. |
| Insert(String, Object, CacheDependency, DateTime, TimeSpan) |
Inserts an object into the Cache with dependencies and expiration policies. |
Insert(String, Object, CacheDependency, DateTime, TimeSpan, CacheItemPriority, CacheItemRemovedCallback)
Inserts an object into the Cache object with dependencies, expiration and priority policies, and a delegate you can use to notify your application when the inserted item is removed from the Cache.
public:
void Insert(System::String ^ key, System::Object ^ value, System::Web::Caching::CacheDependency ^ dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, System::Web::Caching::CacheItemPriority priority, System::Web::Caching::CacheItemRemovedCallback ^ onRemoveCallback);public void Insert (string key, object value, System.Web.Caching.CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, System.Web.Caching.CacheItemPriority priority, System.Web.Caching.CacheItemRemovedCallback onRemoveCallback);member this.Insert : string * obj * System.Web.Caching.CacheDependency * DateTime * TimeSpan * System.Web.Caching.CacheItemPriority * System.Web.Caching.CacheItemRemovedCallback -> unitPublic Sub Insert (key As String, value As Object, dependencies As CacheDependency, absoluteExpiration As DateTime, slidingExpiration As TimeSpan, priority As CacheItemPriority, onRemoveCallback As CacheItemRemovedCallback)Parameters
- key
- String
The cache key used to reference the object.
- value
- Object
The object to be inserted in the cache.
- dependencies
- CacheDependency
The file or cache key dependencies for the item. When any dependency changes, the object becomes invalid and is removed from the cache. If there are no dependencies, this parameter contains null.
- absoluteExpiration
- DateTime
The time at which the inserted object expires and is removed from the cache. To avoid possible issues with local time such as changes from standard time to daylight saving time, use UtcNow rather than Now for this parameter value. If you are using absolute expiration, the slidingExpiration parameter must be NoSlidingExpiration.
- slidingExpiration
- TimeSpan
The interval between the time the inserted object was last accessed and the time at which that object expires. If this value is the equivalent of 20 minutes, the object will expire and be removed from the cache 20 minutes after it was last accessed. If you are using sliding expiration, the absoluteExpiration parameter must be NoAbsoluteExpiration.
- priority
- CacheItemPriority
The cost of the object relative to other items stored in the cache, as expressed by the CacheItemPriority enumeration. This value is used by the cache when it evicts objects; objects with a lower cost are removed from the cache before objects with a higher cost.
- onRemoveCallback
- CacheItemRemovedCallback
A delegate that, if provided, will be called when an object is removed from the cache. You can use this to notify applications when their objects are deleted from the cache.
Exceptions
The key or value parameter is null.
You set the slidingExpiration parameter to less than TimeSpan.Zero or the equivalent of more than one year.
The absoluteExpiration and slidingExpiration parameters are both set for the item you are trying to add to the Cache.
Examples
The following example demonstrates how to assign an item high priority when you insert it into your application's Cache object.
Note
For more information about how to use this method with the CacheItemRemovedCallback delegate, see How to: Notify an Application When an Item Is Removed from the Cache.
Cache.Insert("DSN", connectionString, null, DateTime.Now.AddMinutes(2), TimeSpan.Zero, CacheItemPriority.High, onRemove);
Cache.Insert("DSN", connectionString, Nothing, DateTime.Now.AddMinutes(2), TimeSpan.Zero, CacheItemPriority.High, onRemove)
Remarks
This method will overwrite an existing Cache item with the same key parameter.
You cannot set both the absoluteExpiration and slidingExpiration parameters. If you intend the cache item to expire at a specific time, you set the absoluteExpiration parameter to the specific time, and the slidingExpiration parameter to NoSlidingExpiration.
If you intend the cache item to expire after a certain amount of time has passed since the last access to the item, you set the slidingExpiration parameter to the expiration interval, and the absoluteExpiration parameter to NoAbsoluteExpiration.
See also
Applies to
Insert(String, Object, CacheDependency, DateTime, TimeSpan, CacheItemUpdateCallback)
Inserts an object into the Cache object together with dependencies, expiration policies, and a delegate that you can use to notify the application before the item is removed from the cache.
public:
void Insert(System::String ^ key, System::Object ^ value, System::Web::Caching::CacheDependency ^ dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, System::Web::Caching::CacheItemUpdateCallback ^ onUpdateCallback);public void Insert (string key, object value, System.Web.Caching.CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, System.Web.Caching.CacheItemUpdateCallback onUpdateCallback);member this.Insert : string * obj * System.Web.Caching.CacheDependency * DateTime * TimeSpan * System.Web.Caching.CacheItemUpdateCallback -> unitPublic Sub Insert (key As String, value As Object, dependencies As CacheDependency, absoluteExpiration As DateTime, slidingExpiration As TimeSpan, onUpdateCallback As CacheItemUpdateCallback)Parameters
- key
- String
The cache key that is used to reference the object.
- value
- Object
The object to insert into the cache.
- dependencies
- CacheDependency
The file or cache key dependencies for the item. When any dependency changes, the object becomes invalid and is removed from the cache. If there are no dependencies, this parameter contains null.
- absoluteExpiration
- DateTime
The time at which the inserted object expires and is removed from the cache. To avoid possible issues with local time such as changes from standard time to daylight saving time, use UtcNow instead of Now for this parameter value. If you are using absolute expiration, the slidingExpiration parameter must be set to NoSlidingExpiration.
- slidingExpiration
- TimeSpan
The interval between the time that the cached object was last accessed and the time at which that object expires. If this value is the equivalent of 20 minutes, the object will expire and be removed from the cache 20 minutes after it was last accessed. If you are using sliding expiration, the absoluteExpiration parameter must be set to NoAbsoluteExpiration.
- onUpdateCallback
- CacheItemUpdateCallback
A delegate that will be called before the object is removed from the cache. You can use this to update the cached item and ensure that it is not removed from the cache.
Exceptions
The key, value, or onUpdateCallback parameter is null.
You set the slidingExpiration parameter to less than TimeSpan.Zero or the equivalent of more than one year.
The absoluteExpiration and slidingExpiration parameters are both set for the item you are trying to add to the Cache.
-or-
The dependencies parameter is null, and the absoluteExpiration parameter is set to NoAbsoluteExpiration, and the slidingExpiration parameter is set to NoSlidingExpiration.
Remarks
The Insert method enables you to insert a new item in the cache and provide a delegate that is called before the item is removed from the cache. In the delegate, you can update the cached item and thereby prevent it from being removed from the cache.
This method will overwrite an existing Cache item with the same key parameter.
You cannot set both the absoluteExpiration and slidingExpiration parameters. If you intend the cache item to expire at a specific time, you set the absoluteExpiration parameter to the specific time, and the slidingExpiration parameter to NoSlidingExpiration.
If you intend the cache item to expire after a set period of time since the item was last accessed, you set the slidingExpiration parameter to the expiration interval, and you set the absoluteExpiration parameter to NoAbsoluteExpiration.
See also
Applies to
Insert(String, Object, CacheDependency)
Inserts an object into the Cache that has file or key dependencies.
public:
void Insert(System::String ^ key, System::Object ^ value, System::Web::Caching::CacheDependency ^ dependencies);public void Insert (string key, object value, System.Web.Caching.CacheDependency dependencies);member this.Insert : string * obj * System.Web.Caching.CacheDependency -> unitPublic Sub Insert (key As String, value As Object, dependencies As CacheDependency)Parameters
- key
- String
The cache key used to identify the item.
- value
- Object
The object to be inserted in the cache.
- dependencies
- CacheDependency
The file or cache key dependencies for the inserted object. When any dependency changes, the object becomes invalid and is removed from the cache. If there are no dependencies, this parameter contains null.
Exceptions
The key or value parameter is null.
Examples
The following example demonstrates how to insert an item into an application's cache with a cache dependency on an XML configuration file.
Cache.Insert("DSN", connectionString, new CacheDependency(Server.MapPath("myconfig.xml")));
Cache.Insert("DSN", connectionString, New CacheDependency(Server.MapPath("myconfig.xml")))
Remarks
This method will overwrite an existing cache item whose key matches the key parameter. The object added to the cache using this overload of the Insert method is inserted with a priority of Default, a sliding expiration value of NoSlidingExpiration, and an absolute expiration value of NoAbsoluteExpiration.
See also
Applies to
Insert(String, Object)
Inserts an item into the Cache object with a cache key to reference its location, using default values provided by the CacheItemPriority enumeration.
public:
void Insert(System::String ^ key, System::Object ^ value);public void Insert (string key, object value);member this.Insert : string * obj -> unitPublic Sub Insert (key As String, value As Object)Parameters
- key
- String
The cache key used to reference the item.
- value
- Object
The object to be inserted into the cache.
Exceptions
The key or value parameter is null.
Examples
The following example demonstrates how to insert an item into an application's cache.
Cache.Insert("DSN", connectionString);
Cache.Insert("DSN", connectionString)
Remarks
This method will overwrite an existing cache item whose key matches the key parameter. The object added to the cache using this overload of the Insert method is inserted with no file or cache dependencies, a priority of Default, a sliding expiration value of NoSlidingExpiration, and an absolute expiration value of NoAbsoluteExpiration.
See also
Applies to
Insert(String, Object, CacheDependency, DateTime, TimeSpan)
Inserts an object into the Cache with dependencies and expiration policies.
public:
void Insert(System::String ^ key, System::Object ^ value, System::Web::Caching::CacheDependency ^ dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration);public void Insert (string key, object value, System.Web.Caching.CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration);member this.Insert : string * obj * System.Web.Caching.CacheDependency * DateTime * TimeSpan -> unitPublic Sub Insert (key As String, value As Object, dependencies As CacheDependency, absoluteExpiration As DateTime, slidingExpiration As TimeSpan)Parameters
- key
- String
The cache key used to reference the object.
- value
- Object
The object to be inserted in the cache.
- dependencies
- CacheDependency
The file or cache key dependencies for the inserted object. When any dependency changes, the object becomes invalid and is removed from the cache. If there are no dependencies, this parameter contains null.
- absoluteExpiration
- DateTime
The time at which the inserted object expires and is removed from the cache. To avoid possible issues with local time such as changes from standard time to daylight saving time, use UtcNow rather than Now for this parameter value. If you are using absolute expiration, the slidingExpiration parameter must be NoSlidingExpiration.
- slidingExpiration
- TimeSpan
The interval between the time the inserted object is last accessed and the time at which that object expires. If this value is the equivalent of 20 minutes, the object will expire and be removed from the cache 20 minutes after it was last accessed. If you are using sliding expiration, the absoluteExpiration parameter must be NoAbsoluteExpiration.
Exceptions
The key or value parameter is null.
You set the slidingExpiration parameter to less than TimeSpan.Zero or the equivalent of more than one year.
The absoluteExpiration and slidingExpiration parameters are both set for the item you are trying to add to the Cache.
Examples
The following example demonstrates how to insert an item into an application's cache with an absolute expiration.
Note
Since this form of the Insert method supports cache dependencies, if the item has no dependencies, you must declare the dependency parameter as null (Nothing in Visual Basic) in the comma-delimited list of parameters.
Cache.Insert("DSN", connectionString, null, DateTime.Now.AddMinutes(2), Cache.NoSlidingExpiration);
Cache.Insert("DSN", connectionString, Nothing, DateTime.Now.AddMinutes(2), Cache.NoSlidingExpiration)
The following example demonstrates how to insert an item into the cache with a sliding expiration.
Cache.Insert("DSN", connectionString, null, Cache.NoAbsoluteExpiration, TimeSpan.FromSeconds(10));
Cache.Insert("DSN", connectionString, Nothing, Cache.NoAbsoluteExpiration, TimeSpan.FromSeconds(10))
Remarks
This method will overwrite an existing Cache item with the same key parameter.
If the slidingExpiration parameter is set to NoSlidingExpiration, sliding expiration is disabled. If you set the slidingExpiration parameter to greater than Zero, the absoluteExpiration parameter is set to Now plus the value contained in the slidingExpiration parameter. If the item is requested from the cache before the amount of time specified by the absoluteExpiration parameter, the item will be placed in the cache again, and absoluteExpiration will again be set to DateTime.Now plus the value contained in the slidingExpiration parameter. If the item is not requested from the cache before the date in the absoluteExpiration parameter, the item is removed from the cache. The item added to the cache using this overload of the insert method is inserted with a priority of Default.
